GAMS/Cplex does not solve MIP

[PelinaP]

Error Cannot open parameter file "C:\Users\energy\anaconda3\envs\message_env\Lib\site-packages\message_ix\model\cplex.opt" *** Error Error code = 2; No such file or directory

Code sample or context

I downloaded new version of Message-ix 3.6 and also gams version of 34.3. The cplex model worked fine with gams version 30.3 and message-ix version 3.0 . I would like to find out why i recieve error message GAMS/Cplex Link licensed for continuous and discrete problems.

*** Error Cannot open parameter file "C:\Users\energy\anaconda3\envs\message_env\Lib\site-packages\message_ix\model\cplex.opt" *** Error Error code = 2; No such file or directory

...your code

-->scenario.init_set("kp")

Expected result

feasible solution and cplex should work fine

Problem description

Error message ; Cannot open parameter file "C:\Users\energy\anaconda3\envs\message_env\Lib\site-packages\message_ix\model\cplex.opt" *** Error Error code = 2; No such file or directory

Versions

Gams version 34.3 , message-ix 3.6 ####Output --- Space for names approximately 1.37 Mb --- Use option 'names no' to turn use of names off --- GMO memory 5.87 Mb (peak 5.96 Mb) --- Dictionary memory 0.00 Mb --- Cplex 20.1.0.0 link memory 0.38 Mb (peak 2.68 Mb) --- Starting Cplex

Version identifier: 20.1.0.0 | 2020-11-10 | 9bedb6d68 CPXPARAM_Advance 0 CPXPARAM_Threads 1 CPXPARAM_MIP_Display 4 CPXPARAM_Simplex_Limits_Iterations 100000000 CPXPARAM_TimeLimit 1000000 CPXPARAM_MIP_Tolerances_AbsMIPGap 0 CPXPARAM_MIP_Tolerances_MIPGap 0 Generic callback 0x50 Row 'INTP_CAP(Zambia,'Oil(FO)_ppl',2025)' infeasible, all entries at implied bounds. Presolve time = 0.00 sec. (5.54 ticks)

Root node processing (before b&c): Real time = 0.02 sec. (8.25 ticks) Sequential b&c: Real time = 0.00 sec. (0.00 ticks) ------------ Total (root+branch&cut) = 0.02 sec. (8.25 ticks)

--- MIP status (103): integer infeasible. --- Cplex Time: 0.02sec (det. 8.29 ticks)

CPLEX Error 1217: No solution exists. --- Problem is integer infeasible

<!--
Run one of the following and paste the results here:
- 'message-ix show-versions' in a terminal, or
- 'import ixmp; ixmp.show_versions()' in a Python interpreter.
-->

[volker-krey]

The original GAMS coming with message_ix does not include any mixed integer program (MIP) model specification. If you modified the GAMS code and added a MIP version of message_ix, it is difficult for us to help with that. The error message related to the file cplex.opt not existing should not be the reason for the infeasibility of the problem. cplex.opt is an optional file to set solver-specific options for CPLEX, a subset of which can be set via the Python API.